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Commit f7d79860 authored by Anton Blanchard's avatar Anton Blanchard Committed by Paul Mackerras
Browse files

perf_event: Add alignment-faults and emulation-faults software events 



Add two more software events that are common to many cpus.

Alignment faults: When a load or store is not aligned properly.

Emulation faults: When an instruction is emulated in software.

Both cause a very significant slowdown (100x or worse), so identifying and
fixing them is very important.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 81cd5ae3

include/linux/perf_counter.h

+2 −0
Original line number Diff line number Diff line
@@ -106,6 +106,8 @@ enum perf_sw_ids { 
	PERF_COUNT_SW_CPU_MIGRATIONS		= 4,

	PERF_COUNT_SW_PAGE_FAULTS_MIN		= 5,

	PERF_COUNT_SW_PAGE_FAULTS_MAJ		= 6,

	PERF_COUNT_SW_ALIGNMENT_FAULTS		= 7,

	PERF_COUNT_SW_EMULATION_FAULTS		= 8,



	PERF_COUNT_SW_MAX,			/* non-ABI */

};

include/linux/perf_event.h

+2 −0
Original line number Diff line number Diff line
@@ -102,6 +102,8 @@ enum perf_sw_ids { 
	PERF_COUNT_SW_CPU_MIGRATIONS		= 4,

	PERF_COUNT_SW_PAGE_FAULTS_MIN		= 5,

	PERF_COUNT_SW_PAGE_FAULTS_MAJ		= 6,

	PERF_COUNT_SW_ALIGNMENT_FAULTS		= 7,

	PERF_COUNT_SW_EMULATION_FAULTS		= 8,



	PERF_COUNT_SW_MAX,			/* non-ABI */

};

kernel/perf_event.c

+2 −0
Original line number Diff line number Diff line
@@ -4186,6 +4186,8 @@ static const struct pmu *sw_perf_event_init(struct perf_event *event) 
	case PERF_COUNT_SW_PAGE_FAULTS_MAJ:

	case PERF_COUNT_SW_CONTEXT_SWITCHES:

	case PERF_COUNT_SW_CPU_MIGRATIONS:

	case PERF_COUNT_SW_ALIGNMENT_FAULTS:

	case PERF_COUNT_SW_EMULATION_FAULTS:

		if (!event->parent) {

			atomic_inc(&perf_swevent_enabled[event_id]);

			event->destroy = sw_perf_event_destroy;

tools/perf/design.txt

+2 −0
Original line number Diff line number Diff line
@@ -137,6 +137,8 @@ enum sw_event_ids { 
	PERF_COUNT_SW_CPU_MIGRATIONS	= 4,

	PERF_COUNT_SW_PAGE_FAULTS_MIN	= 5,

	PERF_COUNT_SW_PAGE_FAULTS_MAJ	= 6,

	PERF_COUNT_SW_ALIGNMENT_FAULTS	= 7,

	PERF_COUNT_SW_EMULATION_FAULTS	= 8,

};



Counters of the type PERF_TYPE_TRACEPOINT are available when the ftrace event

tools/perf/util/parse-events.c

+4 −0
Original line number Diff line number Diff line
@@ -46,6 +46,8 @@ static struct event_symbol event_symbols[] = { 
  { CSW(PAGE_FAULTS_MAJ),	"major-faults",		""		},

  { CSW(CONTEXT_SWITCHES),	"context-switches",	"cs"		},

  { CSW(CPU_MIGRATIONS),	"cpu-migrations",	"migrations"	},

  { CSW(ALIGNMENT_FAULTS),	"alignment-faults",	""		},

  { CSW(EMULATION_FAULTS),	"emulation-faults",	""		},

};



#define __PERF_EVENT_FIELD(config, name) \
@@ -74,6 +76,8 @@ static const char *sw_event_names[] = { 
	"CPU-migrations",

	"minor-faults",

	"major-faults",

	"alignment-faults",

	"emulation-faults",

};



#define MAX_ALIASES 8